Printer ductor roller and electromagnetic valve protection member built into ductor roller

ABSTRACT

A ductor roller for printing machines has a shaft provided with an air supply pipe, plural individual ductor rollers, and plural electromagnetic valves, both connected to the shaft. The individual ductor rollers advance pneumatically by the electromagnetic valves. The individual ductor rollers have housings that are associated with the shaft and configured to move forward and backward; roller members configured to contact with the ink fountain roller and an ink distribution roller; and bearings connecting the roller members to the housings. The electromagnetic valves are placed in the housings. Protection members for the electromagnetic valves are oil-resistant, have circularly cylindrical or arc-like covers, and are associated with the shaft. They cover the side ends of the housings and are placed in the clearance between the individual ductor rollers. The protection members do not need an exchange, discharge cleaning liquid for printing machines along troughs and prevent the electromagnetic valves from being contaminated by the cleaning liquid.

FIELD OF THE INVENTION

The present invention relates to a ductor roller for printing machinesand, in particular, to protection members of electromagnetic valvesinstalled in the ductor roller.

BACKGROUND ART

Offset printing machines and letterpress machines are provided with aductor roller between an ink fountain roller and an ink distributionroller; the ductor roller is switched between a state in contact withthe ink fountain roller and the other state in contact with the inkdistribution roller. The ductor roller receives ink when in contact withthe ink fountain roller and delivers the ink when in contact with theink distribution roller. The contact period of the ductor roller withthe ink fountain roller is controlled so that the ink supply amount tothe plate cylinder is controlled.

When the ductor roller comprises plural individual ductor rollers andwhen the individual ductor rollers are controlled so as to independentlymove forward and backward, the ink supply amount is made finelyadjustable in the axial direction of the ink fountain roller (PatentDocument 1: JP 3008026B) . The individual ductor rollers are associatedwith a fixed shaft and advance toward the ink fountain roller by pistonsthat pneumatically advance from the shaft. Further, the individualductor rollers are biased toward the ink distribution roller by springsand contact pieces and return toward the ink distribution roller whenthe air supply is shut down. In addition, electromagnetic valves areinstalled to the fixed shaft for controlling the individual ductorrollers.

When the electromagnetic valves are contaminated by cleaning liquid forprinting machines, ink, or other materials, the correct operation of theelectromagnetic valves may be impeded. Therefore, Patent Document 1discloses to provide oil-resistant rubber products for coveringclearance between the individual ductor rollers to prevent the cleaningliquid and so on from entering into the clearance. In other words, therubber products cover the side ends of the individual ductor rollers soas to shut out the cleaning liquid and so on.

PRIOR ART DOCUMENT LIST Patent Document

Patent Document 1: JP 3008026B

SUMMARY OF THE INVENTION Problem to be Solved by the Invention

The inventors have found that the oil-resistant rubber productsdeteriorate by the cleaning liquid for a short period and have to beexchanged frequently.

The object of the invention is to improve the durability of protectionmembers for electromagnetic valves in ductor rollers for printingmachines.

Means for Solving the Problem

A ductor roller for a printing machine according to the inventioncomprises: a shaft provided with an air supply pipe; a plurality ofindividual ductor rollers; and a plurality of electromagnetic valves.The individual ductor rollers and the electromagnetic valves areconnected to the shaft, and the individual ductor rollers are advancedpneumatically by said electromagnetic valves.

In the ductor roller for a printing machine according to the invention,

the individual ductor rollers are provided with housings associated withthe shaft and configured to move forward and backward; roller membersconfigured to contact an ink fountain roller and an ink distributionroller, both of the printing machine; and bearing members connecting theroller members to the housings,

said electromagnetic valves are placed in said housings, and

protection members for the electromagnetic valves are placed inclearance between the individual ductor rollers, and are oil-resistant,are associated with and supported by the shaft, and are provided withcircularly cylindrical or arc-like covers covering at least upperportions of side ends of said housings. Preferably, the protectionmembers comprise: plate-like portions having association holes that areassociated with said shaft; and said circularly cylindrical or arc-likecovers.

According to the invention, the covers of protection members cover atleast the upper side end portions of the housings and block the cleaningliquid and so on. The covers are circularly cylindrical or arc-like,guide downward the cleaning liquid received by the covers, and preventthe cleaning liquid from reaching the electromagnetic valves. Theprotection members have a constant shape, do not deform such as rubbersdo, and have basically no need for exchange due to their oil-resistance.

Preferably, the covers are circularly cylindrical and have a trough on acircular face of the circularly cylindrical covers, and the trough islow at a central portion of the circularly cylindrical covers and highat side end portions of the circularly cylindrical covers, both in anaxial direction of said shaft. The cleaning liquid adhering to thecovers flows along the troughs and does not intrude to theelectromagnetic valves. Further, the cleaning liquid is discharged tothe outside through the clearance between the individual ductor rollers.

Further preferably, a guide for guiding the cleaning liquid for printingmachines downward is present at a central portion of the trough in theaxial direction. The guide may be a projection or a groove, and thecleaning liquid flows along the guide downward.

Most preferably, at least a projection dropping the cleaning liquiddownward is present at a lower end of the trough. The cleaning liquidreached the lower end of the trough concentrates at and drops from theprojection and is discharged through the clearance between theindividual ductor rollers.

There is such a ductor roller for printing machines that has a shaftprovided with an air supply pipe, plural electromagnetic valves, andplural individual ductor rollers, both connected to the shaft. Theindividual ductor rollers have housings, bearings, and roller members,and the roller members are connected to the housings via the bearings.The individual ductor rollers are advanced toward the ink fountainroller pneumatically by said electromagnetic valves, and theelectromagnetic valves are placed in the housings. The protectionmembers according to the invention are suitable for such ductor rollersfor printing machines. The protection members are oil-resistant and haveassociation holes for association with the shaft and circularlycylindrical covers that cover at least the upper portions of side endsof the housings of the individual ductor rollers. Further, the circularface of the circularly cylindrical covers is provided with a trough thatis lower at the center portion and higher at both end portions in theaxial direction of the circularly cylindrical covers. The covers coverat least a side end of the housing and receive cleaning liquid intrudingthrough the clearance between the individual ductor rollers. Thecleaning liquid flows downward along the trough and is dischargedthrough the clearance between the individual ductor rollers.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 A view indicating the major portion of a ductor roller accordingto the embodiment, and partially an ink fountain roller and an inkdistribution roller at the forward and the back positions.

FIG. 2 A vertical cross-sectional view of the ductor roller in the II-IIdirection in FIG. 1.

FIG. 3 A view indicating a protection member according to the embodimentand housings of individual ductor rollers.

FIG. 4 A front view of the protection member according to theembodiment.

FIG. 5 A cross-sectional view of the protection member in the V-Vdirection in FIG. 3.

FIG. 6 A cross-sectional view of the protection member in the VI-VIdirection in FIG. 4.

FIG. 7 A side view of another protection member according to amodification.

FIG. 8 A cross-sectional view of another protection member according toa second modification.

FIG. 9 A view indicating another protection member according to a thirdmodification and individual ductor rollers at the left and right withoutthe roller members.

FIG. 10 A front view of the protection member according to the thirdmodification.

FEATURES FOR CARRYING OUT THE INVENTION

The best embodiment for carrying out the invention will be described.

Embodiment

FIGS. 1 to 10 indicate the best embodiment and also its modifications.As shown in FIG. 1, a ductor roller 2 according to the embodiment isinstalled between the ink fountain roller 4 and an ink distributionroller 6, and is provided with a fixed shaft 8 and a plurality ofindividual ductor rollers 12 connected to the shaft. Further, in agroove 9 on the upper face of the shaft 8, plural electromagnetic valves10 are placed for each of the individual rollers 12. Between a pair ofthe individual ductor rollers 12 and 12, a protection member 14 isassociated with the shaft 8, covers the side ends of the housings 13 ofthe individual ductor rollers 12, and is placed in the clearance betweenthe individual ductor rollers 12 and 12. In addition, since a row of theindividual ductor rollers 12 are installed on the shaft 8, theprotection members 14 are preferably installed also at both ends of therow of the individual ductor rollers 12.

As shown in FIGS. 2 and 3, each of the individual ductor rollers 12 isprovided with a roller member 16 at the outer circular periphery, theroller member is fixed to the housing 13 via a bearing 18, and thehousing 13 is associated with the shaft 8. The shaft 8 is provided witha pipe 20 for supplying air, and a piston 21 moves forward and backwardpneumatically by the electromagnetic valve 10. At the opposite side ofthe shaft 8 to the piston 21, a contact piece 22, for example, sphericaland a spring 23 are provided, and they make the individual ductor roller12 biased toward the ink distribution roller 6. Furthermore, oneelectromagnetic valve 10 is installed for each of the individual ductorrollers 12, is covered by the housing 13, and controlled by a controllernot shown.

The individual ductor rollers 12 advance pneumatically toward the inkfountain roller 4 and retract by the springs 23 and the contact pieces22 toward the ink distribution roller 6. The directions in thespecification are shown in FIGS. 1 and 2. The up and down direction isdetermined according to the ductor roller 12 installed in a printingmachine, and, according to the embodiment, the electromagnetic valves 10are at the upper portion of the shaft 8. Further, the front indicatesthe side of the ink fountain roller 4, and the back indicates the sideof the ink distribution roller 6. The left and right direction isparallel to the lengthwise direction of the shaft 8. The axial directionis the same to the left and right direction and means the lengthwisedirection of the shaft 8. The protection member 14 is circularlycylindrical, the circular direction of the cylinder is simply called thecircular direction, and the axial direction of the circular cylinder issimply called the axial direction.

FIG. 3 indicates the protection member 14 and the housings 13 of theleft and right individual ductor rollers 12 and 12. The protectionmember 14 comprises an oil-resistant material, such as steel, aluminum,or oil-resistant polymer resin and, according to the embodiment, forweight reduction, it comprises an oil-resistant polymer resin such asnylon or fluoropolymer. The oil-resistance of polymers are remarkablydifferent between rubbers, which are easily deformable, and resins,which have a constant shape, even if they comprise the same monomer.Resins such as nylons, fluoro resins, polycarbonate resins, phenolresins, unsaturated polyester resins, and furan resins have excellentoil-resistance. The protection member 14 covers the side ends of thehousings 13 and prevents contamination matters such as cleaning liquidfrom entering into the housings 13. The protection member 14 accordingto the embodiment has practically no need for exchange.

The structure of the protection member 14 is shown in FIGS. 4 to 6. Theprotection member 14 has a plate-like portion 27 at the center part inthe axial direction and has circularly cylindrical portions 32 and 32 atboth sides of the plate-like portion in the axial direction. Further,within a recess 29 between the cylindrical portion 32 and the plate-likeportion 27, one side end of the housing 13 is placed. 26 indicates theside end surface of the cylindrical portion 32 in the axial direction.The plate-like portion 27 has an association hole 30 through which theshaft 8 extends to position the protection member 14 between a pair ofthe individual ductor rollers 12 and 12. The inner diameter of thecylindrical portion 32 (the diameter of the recess 29 ) is a bit largerthan the outer diameter of the housing 13 and this allows the housing 13moves back and forth.

On the circular surface of the cylindrical portion 32, there is presenta ring-like guide 25 at the central portion in the axial direction, and,at both sides of the ring, there is present a trough 24 that is highertoward the edge portions and lower toward the central portion in theaxial direction. The trough 24 prevents mist of the cleaning liquid andso on from scattering when the mist and so on collide. The cleaningliquid adhering on the trough 24 is downward guided by the guide 25along the trough 24. There is a projection 28 at the lower end of theguide 25, and the cleaning liquid drops from the projection 28 and isdischarged into the clearance between the roller members 16, 16.

The functions of the embodiment will be described. The protectionmembers 14 are oil-resistant and have no need for exchange. The innerdiameter of the cylindrical portion 32 is a bit larger than the outerdiameter of the housing 13 and allows the forward and backward movementof the individual ductor rollers 12. When cleaning the printing machine,the cleaning liquid (the main component is an organic solvent or amachine oil.) is sprayed onto the ductor roller 2, collides the trough24 through the clearance between the roller members 16, 16, is preventedfrom scattering toward the housing 13, and is released along the trough24. At the lower end of the guide 25, the cleaning liquid drops from theprojection 28 and falls through the clearance between the roller members16, 16. Thus, the intrusion of the cleaning liquid to theelectromagnetic valves 10 is prevented. While ink mist and othercontaminants adhere also on the trough 24, they are released with thecleaning liquid and so on to the outside.

FIG. 7 indicates another protection member 34 according to amodification. The protection member 34 is provided with a groove at thecenter portion of the trough 24 to guide the cleaning liquid. In otherrespects, the protection member 34 is the same as the protection member14 in FIGS. 1-6.

FIG. 8 indicates another protection member 44 according to a secondmodification. The protection member 44 has a plurality of projections 48at the lower end of the guide 25 in order to drop the cleaning liquid.In other words, the projection at the lower end of the trough 24 of theprotection members is enough if it receives the cleaning liquid from theguides 25, 35 and drops the cleaning liquid downward. The protectionmember 44 is the same as the protection member 14 in FIGS. 1-6 in otherrespects.

FIGS. 9 and 10 indicate another protection member 54 that is notprovided with the trough 24, the guide 25, nor the projection 28. Theprotection member 54 is provided with an arc-like cover 56 at its upperportion; the cover receives the cleaning liquid and drops it from thelower end of the protection member 54.

According to the embodiment, the individual ductor rollers 12 areretracted by the spring 23 and the contact piece 22, but they may beretracted by the pistons 21 retracting pneumatically.

List of the Symbols 2 ductor roller 4 ink fountain roller 6 inkdistribution roller 8 shaft 9 groove 10 electromagnetic valve 12individual ductor roller 13 housing 14 protection member 16 rollermember 18 bearing 20 pipe 21 piston 22 contact piece 23 spring 24 trough25 guide 26 side surface 27 plate-like portion 28 projection 29 recess30 association hole 32 cylindrical portion 34 protection member 35 guide44 protection member 48 projection 54 protection member 56 cover

1. A ductor roller for a printing machine comprising: a shaft providedwith an air supply pipe; a plurality of individual ductor rollers; and aplurality of electromagnetic valves, wherein the individual ductorrollers and the electromagnetic valves are connected to the shaft, andwherein the individual ductor rollers are advanced pneumatically by saidelectromagnetic valves, wherein the individual ductor rollers areprovided with housings associated with the shaft and configured to moveforward and backward; roller members configured to contact an inkfountain roller and an ink distribution roller, both of the printingmachine; and bearing members connecting the roller members to thehousings, wherein said electromagnetic valves are placed in saidhousings, and wherein protection members for the electromagnetic valvesare placed in clearance between the individual ductor rollers, and areoil-resistant, are associated with and supported by the shaft, and areprovided with circularly cylindrical or arc-like covers covering atleast upper portions of side ends of said housings.
 2. The ductor rollerfor a printing machine according to claim 1, wherein said protectionmembers comprise: plate-like portions having association holes that areassociated with said shaft; and said circularly cylindrical or arc-likecovers.
 3. The ductor roller for a printing machine according to claim1, wherein said circularly cylindrical or arc-like covers are circularlycylindrical and have a trough on a circular face of the circularlycylindrical covers, and wherein the trough is low at a central portionof the circularly cylindrical covers and high at side end portions ofthe circularly cylindrical covers, both in an axial direction of saidshaft.
 4. The ductor roller for a printing machine according to claim 3,wherein a guide for guiding cleaning liquid for printing machinesdownward is present at a central portion of the trough in the axialdirection.
 5. The ductor roller for a printing machine according toclaim 3, wherein at least a projection dropping cleaning liquid forprinting machines downward is present at a lower end of the trough.
 6. Aprotection member for protecting an electromagnetic valve in a ductorroller for a printing machine, wherein the ductor roller comprises: ashaft provided with an air supply pipe; a plurality of individual ductorrollers comprising housings, bearings, and roller members connected tothe housings via the bearings; and a plurality of electromagneticvalves, wherein the individual ductor rollers and the electromagneticvalves are connected to the shaft, wherein the individual ductor rollersare advanced pneumatically by said electromagnetic valves toward an inkfountain roller of the printing machine, and wherein saidelectromagnetic valves are placed in said housings, wherein theprotection member is oil-resistant, is provided with an association holefor association with the shaft, and is provided with a circularlycylindrical cover for covering at least an upper portion of side end ofthe housing of the individual ductor roller and having a trough on acircular face of the circularly cylindrical cover, and wherein thetrough is low at a central portion of the circularly cylindrical coverand high at side end portions of the circularly cylindrical cover in anaxial direction of the circularly cylindrical cover.